bug#48213: offlineimap build fails

[Bone Baboon]

>> This would accommodate Guix users who have disabled ipv6.
>
> Guix doesn't virtualise the kernel and expects it to provide all that
> is needful.  Linux offers knobs for *everything*; that doesn't mean
> everything is supported.  Disabling kernel support for basic things
> (namespaces, UNIX domain sockets, IPv6) *will* break certain software.
>
> We shouldn't feel obligated to accommodate strange configurations out
> of the box, but we try to do so when the maintenance cost is very low.
> In this case, you'd need to ensure the test still runs on the vast
> majority of systems with IPv6.

Sorry I should have explained the rationale for this in my initial
message.

For privacy conscious individuals one tool for improving online privacy
is a VPN service. Many VPN service providers recommend disabling
ipv6. This is because of ipv6 leaks. 

https://ipv6leak.com/ is a ipv6 leak testing site.  It is the first
result when searching for "ipv6 leak" with searx.ir.  Using this website
I can see that the privacy provided by my VPN service provider is
compromised by an ipv6 leak when I enable ipv6.  This is why I have ipv6
disabled.

I am open to suggestions on free software alternatives to using a VPN
service that do not require ipv6 to be disabled. The current VPN service
I am using allows the use of a openvpn client so I do not need to
install any proprietary software on my computer to use their service.  I
am aware of Tor or I2P but have not yet looked into how I could to send
my network traffic over those networks.